At the latest when a child starts school, they begin to compare themselves with others – including in terms of height. «I'm the smallest in the class,» your son might say. But does that mean he is below average height or has a disorder?
«It's quite possible that the child was simply unlucky and happened to end up in a school class with lots of tall or older children,» says Urs Eiholzer. The specialist in paediatrics and adolescent medicine is the founder and director of the Paediatric Endocrinology Centre Zurich (PEZZ), Switzerland's leading practice for growth and hormone disorders. But perhaps the boy really is small – «because his parents are also small,» says the specialist.
Suspected growth disorders in babies and teenagers are among the most common reasons why parents visit a paediatrician. However, very few children actually suffer from a growth disorder: only three per cent are short or tall. Nevertheless, endocrinology consultations – during which it is determined whether a child's growth is normal – are very busy. This is because there is also a grey area: this includes children who are not considered short or tall from a purely medical point of view, but who feel that they are.
How tall will my child be?
For girls: (father's height – 13 cm)/2 + mother's height/2
For boys: (mother's height + 13 cm)/2 + father's height/2
Growth is individual
«Generally speaking, there are two phases of rapid growth,» says Stefanie Graf, a paediatric endocrinologist at her own practice, Endonet, in Basel and at Aarau Cantonal Hospital. The first is during the first year of life, when infants double their height, and the second is later during puberty.
However, this growth spurt occurs earlier in girls than in boys, and they also reach full height earlier, at an average age of 15 to 16. Boys, on the other hand, often do not experience their main growth spurt until they are 13 to 14 years old and usually reach full height at 17 to 18 years of age.
If the mother or father was late to grow, this will probably also be the case for the child.
However, the emphasis is on «most» – because these are only average values, which can vary greatly in individual cases. «There are early developers and late developers,» emphasises Eiholzer. «This is important to know in this context.» In some children, the body is in a hurry, development is accelerated, and biological age is ahead of chronological age.
Puberty therefore begins earlier and the child reaches full height sooner. Conversely, however, the body can also set a slower pace – development is then delayed, puberty begins later, the child grows for longer and reaches full height later than the average for their age group. «All of this usually happens without there being any disorder,» says Eiholzer.
Sudden deviation as a signal
But what determines a child's growth? Depending on the stage of life, various factors – such as nutrition or hormones – have different degrees of influence. « Genetics also play a major role here,» says Stefanie Graf. «If the mother or father were late bloomers, there is a higher probability that this will also be the case for the child.» The height of the parents is also usually an indication of the expected height of their offspring.
But when should you actually go to the doctor because of height? As a rule, it is paediatricians who notice any abnormalities and refer affected children to specialists such as Stefanie Graf or Urs Eiholzer. Paediatricians see their patients regularly, keep growth charts over a long period of time and are therefore the first to notice any deviations.
Chronic illnesses can inhibit growth. However, with early treatment, a child can grow to a normal height.
«In the case of a child who has always been in the lower percentile range but has a good growth rate, everything is usually fine,» says Graf. However, if the curve suddenly dips and growth stagnates, it is necessary to take a closer look. This also applies if growth suddenly accelerates outside of the physiological growth phases. Slower growth is much more common, however.
A hand X-ray can then be used to determine a child's bone age in a first step. This is compared with their actual age in order to make a growth prognosis and decide whether the growth delay needs to be treated.
«In all likelihood, a child who is too small and has delayed bone age is simply a late developer,» says Urs Eiholzer, speaking from experience. But this is not always the case. «In about one in every hundred cases, there is an underlying growth disorder that needs to be treated.»
What do growth curves show?
"It is important to use current growth curves from the region,» says Urs Eiholzer. He has worked to ensure that there are new growth curves for children in Switzerland. The specialist in paediatrics and adolescent medicine is the founder and director of the Paediatric Endocrinology Centre Zurich (PEZZ).
Why does Switzerland need its own curves? «Monitoring growth is a key task for paediatricians. They can only fulfil this task if they have access to standard values that reflect the normal growth of their own population as accurately as possible.» This is the only way to distinguish normal growth from abnormal growth. In general, it can be said that «the further south people live, the smaller and heavier they are, and the further north, the taller and slimmer they are.» That is why Italy has two growth charts, one for northern Italy and one for southern Italy. «With the data we collect in Switzerland, we can accurately map growth."
Cause of growth disorders
There are more than 2,500 genetic disorders that cause short stature – and only three that cause tall stature. Children who are too small often have chronic conditions such as coeliac disease, i.e. gluten intolerance. Intestinal diseases such as Crohn's disease can also delay growth, as can an underactive thyroid.
In these cases, the first step is to treat the chronic illness. «If this is done early on, there is a good chance that the child will ultimately grow to the height inherited from their parents,» says Eiholzer. However, taking certain medications can also inhibit growth in children – for example, if the dose of cortisone in asthma sprays is too high. «Cortisone is a very potent hormone. If a child has had too much of it, it is often impossible to catch up on growth.»
Stefanie Graf also sees many children in her practice who are involved in competitive sports. «In these cases, slow growth is often an energy supply problem,» says the doctor. «Anyone who trains four times a week, has an additional match at the weekend and does not pay attention to their diet with sufficient calorie intake will find that their body switches to economy mode. This can slow down puberty.»
This also applies to children who participate in sports such as ballet and artistic gymnastics, where it is sometimes desirable not to weigh too much. In these cases, slow growth is often not due to a hormonal or congenital problem. «Instead, the body regulates itself down because it is in a state of energy deficiency.» An adequate supply of nutrients can stimulate growth again.
Boys are often fixated on a final height of 180 centimetres or more.
Stefanie Graf, endocrinologist
Now the young people are asking
In recent years, however, the importance of height has become increasingly significant. «More and more parents are feeling uncertain and afraid that their child is not growing properly,» observes Urs Eiholzer. «The need for appropriate advice has increased significantly.»
Stefanie Graf adds: «In the past, it was mainly parents or paediatricians who approached us. Now it's the children themselves who ask: «Will I grow any more?» and «Can anything be done about the fact that I'm so short?»» This is also due to all the images and role models that children and young people consume on social media – because filtered and optimised images can put them under a lot of pressure.
The period between the ages of 10 and 14 is often particularly difficult for boys. Appearances and one's own reflection suddenly become relevant. Boys who are late developers and find themselves surrounded by girls who are already two years ahead of them in their physiological development and are already largely physically mature women, as well as other boys of the same age who are significantly more developed, may feel insecure and ask themselves: Am I normal?
What is behind growing pains?
"Children move around a lot at this age,» says the doctor. «If you've been running around all day and exerting yourself, your muscles are going to ache in the evening.» This could be due to increased strain or poor posture. His advice: «Get some sleep and use some cream – that always helps.»
«Boys who come to my consultation hours are often fixated on a final height of 180 centimetres or more,» observes Graf. «They experience a great deal of stress when the prognosis is below their desired final height. Their hope is that we will give them growth hormones to adjust their bodies.»
But of course, it's not that simple. Families need to be given good advice and children need to be helped to build their self-confidence – to understand that they are just right the way they are and can be happy about their healthy bodies. «These are sometimes difficult discussions,» says the doctor, «because there are certain ideas about lifestyle medicine that supposedly allow the body to be optimised at will.»
Hormone therapy as a miracle cure?
However, endocrinologists cannot perform miracles. Ultimately, genetics determine a person's final height, which is predetermined by their family history – and this cannot be changed. Growth hormone therapy is only successful in cases of congenital hormone deficiencies and a few other indications. Only then will the IV or health insurance cover the costs. «But growth hormone naturally sounds like a miracle cure, so many people have high hopes,» says Graf. «Some parents even offer to pay for the therapy out of their own pockets.»
However, if young men suffer greatly from delayed growth, it is possible to induce puberty with low doses of testosterone. «This leads to an immediate growth spurt, meaning that those affected do not have to wait years for puberty to begin,» says Urs Eiholzer. At the same time, he emphasises: «Such treatment does not lead to an improvement in inherited final height – it merely leads to it being reached more quickly.»
book recommendation
Stefanie Graf always asks her young male patients who feel too small: «Who are you comparing yourself to?» If there is a growth delay, the bone age of a twelve-year-old boy may only correspond to that of a ten-year-old. In that case, he should actually compare himself to them. Graf tries to reassure him in such cases: «At the moment, you may be one of the smaller ones in your year group, but you will catch up – and then you will simply grow for one or two years longer than the others.»
